In 1768, the Gurkhas - a tribe of the Western Himalayas, conquered the Nepal valley. Slowly they built up a powerful State with considerable military strength and desire to expand. On the northern side they were checked by the Chinese Empire and on the southern side the Gurkhas extended their dominion as far as River Tista on the east and Sutlej on the west. The Gurkhas got in possessions the whole of strong country which skirts the northern frontier of Hindustan.
In 1801, the East India Company occupied the Gorakpur district with which the Gurkhas in Tarai became conterminous with the uncertain and ill-defined northern frontier of the British dominions. At the times of Lord Minto, the Gurkhas conquered Bhutwal lying north. However the Company again regained Bhutwal. Thus the conflicting interest between the Gurkhas and the English continued sowing the seeds of the war.
In May 1814, the Gurkhas attacked the three police stations in Bhutwal. Then in October, Governor-General Lord Hastings declared a war against the Gurkhas. Lord Hastings himself took the charge of the war and decided to attack the Gurkhas at the four points along the entire line of Sutlej to the Kosi. The British even tried to bribe the Nepalese Government. But to vanquish the Nepalese was not an easy task for Lord Hastings. Again it was very difficult for the British soldiers to go through the mountainous region.
Treaty of Sagauli - 1815
In 1814-1815, the British had to accept defeats. Major-Generals Marley and John Wood, who were to advance towards Nepal capital, retreated after some unsuccessful attempts. General Gillespie lost his life in Kalanga. Major-General Martindell was defeated at Jaitak. However all these defeats were again retrieved when in April 1815, Colonel Nicolls and Gardener captured Almora in Kumaon and on May 15, 1815, General Ochterlony compelled the Gurkha leader Amar Singh Thapa, to surrender the fort of Malaon. And finally on November 28 1815, the Gurkhas signed a treaty of Sagauli. The Nepal Government hesitated to ratify the treaty and the hostilities began again. General Ochterlony advanced towards the Nepal capital and defeated the Nepalese at Makwanpur on February 28, 1816. This compelled the Nepal Government to ratify the treaty. As per the treaty the Nepalese gave up their claims to places in the lowlands along the southern frontier, gave away Garhwal and Kumaon on the west of Nepal to the British and also withdrew from Sikkim. They also agreed to receive a British Resident at Katmandu. The Nepal Government ever since remained true to its alliance with the English.